[PATCH] f2fs: do not allow partial truncation on pinned file

From: Jaegeuk Kim
Date: Sat Jan 08 2022 - 11:46:00 EST


If the pinned file has a hole by partial truncation, application that has
the block map will be broken.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/file.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index f39feedc9816..6ccdd6e347e2 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1750,7 +1750,11 @@ static long f2fs_fallocate(struct file *file, int mode,
(mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE)))
return -EOPNOTSUPP;

- if (f2fs_compressed_file(inode) &&
+ /*
+ * Pinned file should not support partial trucation since the block
+ * can be used by applications.
+ */
+ if ((f2fs_compressed_file(inode) || f2fs_is_pinned_file(inode)) &&
(mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_COLLAPSE_RANGE |
FALLOC_FL_ZERO_RANGE | FALLOC_FL_INSERT_RANGE)))
return -EOPNOTSUPP;
--
2.34.1.575.g55b058a8bb-goog